Bartamos,
Yes, actual engine serial numbers ended with the 1956 model year.
You are absolutely correct with the term "Engine number suffix codes"...nothing about this number makes it a "serial number" or a "VIN" as way more than one engine would/could have the same code...Example F1102YS built in Flint, on Nov 2nd, with the same application code for a 1967 327 Model C-10, 20 & 30. How many C-10 327 engines were built that day? I bet way more than one!
Mike B
